In some cases, an extension to a residential property can be considered to be a permitted development, which does not require a planning application to be submitted. However, it is subject to certain limits and conditions.
What limits and conditions apply?
• If any part of the extension is not higher than the highest part of the roof of the existing property
• If the eaves of the extension are not higher than the eaves of the existing property
• If the materials used in the exterior work are of similar appearance to the existing property
• If any part of the extension does not extend beyond any wall facing a road, if it forms the principal or side elevation of the original property
• If the eaves are no more than 3m in height, if any part of the extension is within 2m of the property boundary
• If an upper floor window on a side elevation within 15m of a boundary with another house is obscure glazed and is non-opening; unless the parts which can be opened are more than 1.7m above the floor of the room in which the window is installed
• If a side extension does not exceed 4m in height or is wider than half the width of the original property.
Does it depend on the dwelling?
In a single-storey extension:• If the extension does not extend beyond the rear wall of the original house by more than 4m for a detached house, or 3m for any other type of house
• If the height of the extension does not exceed 4m
• If no part of the extension is within 3.5m of any property boundary with a road opposite the rear wall of the house.
In an extension with more than one storey:• If the extension does not extend beyond the rear wall of the original property by more than 3m
• If no part of the extension is within 7m of the property boundary opposite the rear wall of the property
• If the roof pitch of the enlargement is as far as practicable the same as that of the original property.
What is the planning law if I live in a listed building?
If you live in a property which is a listed building you will need to apply for a Listed Building Consent for any building operations you wish to carry out. However, if the development is within the curtilage of a listed building, you may need to submit a planning application for the work, unless listed building consent has already been granted.